Online Dictonaries

Japan Knowledge http://purl.lib.uiowa.edu/japanknowledgeThis reference sources database includes 字通、日本国語大辞典、数え方の辞典、デジタル大辞泉、日本大百科全書(ニッポニカ)、Encyclopedia of Japan、Imidas、現代用語の基礎知識、日本人名大辞典 and many more ditcitionaries. Knowledge Searcher function could help you use Japanese reference sources.